Free Unix Timestamp Tool

Summary

A Unix timestamp tool shows the current epoch time and converts timestamps to calendar dates and back. To use this one free and privately, type a number into Convert Timestamp to Date and read the moment in your local time, UTC, five cities and ISO 8601, or pick a date under Convert Date to Timestamp and press the copy button. Everything runs in your browser, so nothing you enter is uploaded; the Network tab in DevTools will confirm it.

A Unix timestamp, also called epoch time, is the number of seconds since 00:00:00 UTC on 1 January 1970. In seconds it has 10 digits for every date from September 2001 to November 2286; in milliseconds, which is what JavaScript's Date.now() returns, it has 13. One checkbox, Use milliseconds, switches every panel on the page between the two. If you only want a conversion, the timestamp converter focuses on that; this page adds time arithmetic, comparison and a countdown.

Table of Use: Common Timestamp Jobs

The unit decides the digit count. For the same moment, 15 January 2024 at 12:00 UTC:

Features of the Unix Timestamp Tool

• Current timestamp: the current Unix time in seconds or milliseconds, refreshed once a second, with a copy button and the matching local date and time.
• Timestamp to date: one value shown in your local time, UTC, New York, Los Angeles, Paris, Kolkata and Tokyo, plus a copyable ISO 8601 string. The city rows use real time zones, so daylight saving is applied where it applies.
• Unit hints and range checks: a notice when the digits suggest the other unit, and an error beyond about 273,000 years either side of 1970.
• Date to timestamp: a date, an optional time to the second, and a choice between your local time and UTC.
• Add/Subtract Time: start from now or from a timestamp and add or subtract seconds, minutes, hours, days or weeks. The sum and the difference appear together.
• Compare Timestamps: the difference in days, hours, minutes and seconds, a total, and which timestamp is later.
• Countdown to Timestamp: time remaining until a future value, or how long ago a past one was, updating every second.
• Time Units in Seconds reference: a day is 86,400, a week 604,800 and a 365-day year 31,536,000.

Timestamp fields accept a minus or plus sign, decimals and spaces, commas or underscores as digit separators. The formulas are plain: Unix seconds = (moment − 1970-01-01 00:00:00 UTC) in seconds, milliseconds = seconds × 1,000, result = start ± amount × unit length, and difference = second − first. The countdown compares against your device clock.

How to Use the Unix Timestamp Tool

1. Read the Current Unix timestamp card at the top and press Copy to take it. Tick Use milliseconds (applies to every panel) if your data has 13 digits.
2. To read a value, type it into Unix timestamp under Convert Timestamp to Date. Use the clipboard icon beside ISO 8601 (UTC) to copy that string.
3. To get a timestamp, choose a Date, add a Time (optional), pick Your local time or UTC after Date is in, and copy the result.
4. In Add/Subtract Time, leave Start from timestamp blank to use now, set Amount and Unit, and read the plus and minus results.
5. In Compare Timestamps, enter the First timestamp and Second timestamp and read Difference.
6. In Countdown to Timestamp, enter a Target timestamp to see what remains.

Who Can Use It

Developers use it to check API responses and token claims, since the exp and iat values in a JSON Web Token are Unix timestamps in seconds. If the payload is a mess, tidy it first with the JSON formatter, or pull timestamps out of a long log with the regex tester.

Sysadmins line up events across servers in different zones; the time zone converter and the world clock cover the human-readable side. Testers can generate boundary values such as the 2038 limit, and plan recurring jobs with the cron expression generator.

For calendar days, months and working days between two dates, the date difference calculator fits better, and the age calculator handles birthdays. To count down to an event by plain date, use the countdown timer.

FAQs

What is a Unix timestamp?

A Unix timestamp, also called epoch time or POSIX time, is the number of seconds that have passed since 00:00:00 UTC on 1 January 1970. It is the same number everywhere on Earth at a given moment, which is why logs, databases and APIs store it. Leap seconds are not counted: every day is exactly 86,400 seconds. The time zone only matters when you turn the number back into a calendar date.

How do I convert a Unix timestamp to a date?

Type or paste the number into the Unix timestamp field under Convert Timestamp to Date. The tool shows that moment in your local time, UTC, New York, Los Angeles, Paris, Kolkata and Tokyo, plus an ISO 8601 string you can copy. A 10-digit value is read as seconds. For a 13-digit value, tick Use milliseconds first; the tool also shows a hint when the digit count suggests the other unit.

How do I tell if a timestamp is in seconds or milliseconds?

Count the digits. Ten digits is seconds and thirteen is milliseconds for any date from 9 September 2001 to 20 November 2286. Sixteen digits is usually microseconds and nineteen nanoseconds; remove the last three or six digits to get milliseconds. Reading a seconds value as milliseconds lands in January 1970: 1705320000 becomes 20 January 1970 instead of 15 January 2024.

How do I convert a negative Unix timestamp?

Type it with a minus sign. Negative timestamps are dates before 1 January 1970: -86400 is 31 December 1969 at 00:00:00 UTC. The tool accepts any value a JavaScript date can hold, about 273,000 years either side of 1970, and also takes decimals such as 1705320000.5 and digit separators such as 1,705,320,000.

Why does my converted time look wrong or off by some hours?

A timestamp has no time zone, so the same number shows different clock times in different places. If you are off by whole hours, you are probably comparing local time with UTC. When converting a date to a timestamp, choose Your local time or UTC under Date is in, because the two give different numbers.

Does adding 1 day to a timestamp account for daylight saving time?

No. Add/Subtract Time counts a day as exactly 86,400 seconds and a week as 604,800 seconds, so adding 1 day always adds 24 hours. If your clocks change between the start and the result, the local clock time can end up an hour different from "same time tomorrow". The result card shows the local date and time beside the timestamp, so you can see the shift.

What is the Year 2038 problem?

Systems that store Unix time as a signed 32-bit integer can only count up to 2,147,483,647 seconds, which is 03:14:07 UTC on 19 January 2038. One second later the value overflows. Modern systems use 64-bit timestamps, which do not run out for billions of years. You can check the boundary by entering 2147483647 in Convert Timestamp to Date.

Is it safe to paste timestamps from my logs into this tool?

Yes. The tool makes no network requests while you type. The clock, conversions and calculations use your browser's built-in Date and Intl features, and nothing you enter is uploaded or saved. You can check this in the Network tab of DevTools. Reloading the page clears every field.